board/ACube/common/cmd_boota.c - u-boot-sam460ex - Git at Google

 /* cmd_boota.c , AKA the AOS 4.x primary bootloader.
    Idea, design and (broken) code by Andrea Vallinotto.
    Have fun, have phone, have gun, etc...
 */

 #include <common.h>
 #include <command.h>
 #include "cmd_boota.h"
 #include "sys_dep.h"
 #include "slb/sbl_errcodes.h" //For the error codes.
 #include <malloc.h>
 #include "net.h"
 #include <../net/tftp.h>
 #include <asm/processor.h>
 #include <asm/io.h>
 #include <asm/mmu.h>
 #include <asm/4xx_pcie.h>
 #include <asm/gpio.h>

 #undef DEBUG
 #ifdef DEBUG
 #define PRINTF(fmt,args...)	printf (fmt ,##args)
 #else
 #define PRINTF(fmt,args...)
 #endif

 #define MAX_BLOCKSIZE 32768 //This is the PHYSICAL size, not logical!!
 #define ENV_VAR_BUFLEN 256

 extern int console_col; /* cursor col */
 extern int console_row; /* cursor row */

 static char * blockbuffer ; //IO buffer used many times.

 static void interpret_sbl_failure(const WORD err)
      /* Codes are as follows:
 	(see slb/sbl.h)
      */
 {
 	char * stringout;

 	switch(err)
 	{
 		case SBL_COULDNT_INIT:
 			stringout = "Couldn't initialize second-level bootloader (out of memory ?).\n";
 			break;

 		case SBL_PROTOCOL_TOO_OLD:
 			stringout = "Second level bootloader is too old; please upgrade it.\n";
 			break;

 		case SBL_PROTOCOL_TOO_NEW:
 			stringout = "Second level bootloader requires a newer BIOS version; please upgrade.\n";
 			break;

 		case SBL_NO_CONFIG_FILES_FOUND:
 			stringout = "No configuration file found in any partitions.\n";
 			break;

 		case SBL_FAILED_LOADING_KERNEL_IMAGE:
 			stringout = "Failed loading kernel (or kickstart) image file(s).\n";
 			break;

 		case SBL_UNKNOWN_ERROR:
 		default:
 			stringout = "Unknown return code from secondary bootloader.\n";
 			break;
 	}

 	printf(stringout);
 }

 static BOOL good_checksum(const LONG * bl, const UWORD len)
 {
 	ULONG chsum=0;
 	UWORD cnt;

 	for(cnt=0;cnt<len;cnt++)
 		chsum+=*bl++;

 	return (BOOL)(chsum==0);
 }

 static BOOL is_good_bootsector(const struct BootstrapCodeBlock * const bcb,
 			const unsigned long blocksize)
 {
 	//printf("Entered is_good_b.\n");
 	if(bcb->bcb_ID == IDNAME_BOOTSTRAPCODE)
 	{
 		if(bcb->bcb_SummedLongs <= (blocksize>>2))
 		{
 			if(good_checksum((const LONG * const)bcb, bcb->bcb_SummedLongs))
 			    return TRUE;
 			else
 			{
 			    gpio_config(30, GPIO_OUT, GPIO_SEL, GPIO_OUT_1);
 			    printf("Bad checksum while reading second level bootloader\n");
 			}
 		}
 		else printf("Bad block structure while reading second level bootloader: summedlongs not good: %lu instead of %lu\n", bcb->bcb_SummedLongs, blocksize>>2);
 	}
 	// else printf("Bad identifier\n");
 	//bcb_Next is not checked. Too complex.

 	return FALSE;
 }

 static ULONG find_secondary_bootloader_start_HD(const unsigned long blocksize)
 {
 	ULONG currsec = 0;

 	PRINTF("Entered find_sec_bl_start %d %p\n",blocksize,blockbuffer);

 	if ( ! blocksize) return (ULONG)-1;
 	if ( ! blockbuffer) return (ULONG)-1;

 	while(loadsector(currsec, blocksize, 1, blockbuffer))
 	{
 		PRINTF("Reading sector %lu\n", currsec);

 		if(is_good_bootsector((struct BootstrapCodeBlock *)blockbuffer, blocksize))
 			return currsec;

 		/* printf("Sector %lu is bad: signature is %lx (should be %x)\n", currsec,
 	       *((ULONG *)blockbuffer), IDNAME_BOOTSTRAPCODE);
 		*/
 		if(++currsec > SBL_HIGHEST)
 			return (ULONG)-1;
 	}
 	PRINTF("Loadsector failed\n");

 	return (ULONG)-1; //This means a read error.
 }

 static ULONG secondary_bootloader_length(ULONG start_sect, const UWORD blocksize, ULONG * const dest_len)
 {
 	ULONG next = start_sect, res=0;
 	BOOL readres;
 	struct BootstrapCodeBlock * bcb = (struct BootstrapCodeBlock *)blockbuffer;

 	do	{
 		readres = loadsector(next, blocksize, 1, blockbuffer);

 		if(!readres)
 		{
 			//printf("Bad IO while counting sectors for the s.bootloader image.\n");
 			*dest_len = res;
 			return (READ_ERROR|(next & 0xffff));
 		}

 		if(!is_good_bootsector((struct BootstrapCodeBlock *)blockbuffer, blocksize))
 			return (READ_SYNTAX_ERR|next);

 		/*
 		  if(res == 0) //First sector ? Then record start address (first longword)
 		  {
 		    struct BootstrapCodeBlock * helper = blockbuffer;
 		    *start_address = helper->bcb_LoadData[0]; //First longword of first block.
 		  }
 		*/
 		res++;
 	}
 	while((next=bcb->bcb_Next) != UNUSED_BLOCK_ADDRESS);

 	res--; // Excludes last sector.
 	res *= (blocksize - HEADER_INFO_SIZE); // -20 is to exclude header information.
 	res += ((bcb->bcb_SummedLongs<<2) - HEADER_INFO_SIZE); //Last sector.

 	*dest_len = res;
 	return LOAD_OK;
 }

 static void load_secondary_bootloader(ULONG start_sect, char * dest_buffer, const UWORD blocksize,
 				      const ULONG len)
 {
 	/* No error check is made, so be careful everything's ok before calling */
 	ULONG nextsec=start_sect, chunklen;
 	char * copystart = blockbuffer + HEADER_INFO_SIZE;
 	ULONG * current = (ULONG *)dest_buffer;
 	struct BootstrapCodeBlock * bcb = (struct BootstrapCodeBlock *)blockbuffer;

 	do
 	{
 		loadsector(nextsec, blocksize, 1, blockbuffer);
 		//lprintf("Reading sector %lu for lseg image\n", nextsec);
 		//mycopymem(copystart, (char *)current, (chunklen=bcb->bcb_SummedLongs-(HEADER_INFO_SIZE>>2))<<2);
 		memcpy((char *)current, copystart, (chunklen=bcb->bcb_SummedLongs-(HEADER_INFO_SIZE>>2))<<2);
 		current+=chunklen;
    }
 	while((nextsec=bcb->bcb_Next) != UNUSED_BLOCK_ADDRESS);
 }

 static void start_secondary_bootloader(void * start, struct sbl_callback_context * context)
 {
 	WORD (* bls)(struct sbl_callback_context *);
 	//void * realstart = ((char *)start)+4; //To skip the header. Remove for final version.
 	//((char *)start)+offset;
 	unsigned long entrypoint;
 	WORD result;

 	//icache_enable();
 	//printf("Second-level bootloader loaded at %p; now checking.\n", start);
 	//if(!valid_elf_image(realstart))
 	if(!valid_elf_image(start))
     {
 		printf("Error: no real ELF image installed as bootloader!\n");
 		return;
 	}
 	//else printf("Image file is valid! Now elf-loading & relocating.\n");

 	//entrypoint = load_elf_image(realstart);
 	entrypoint = load_elf_image(start);
 	bls = (WORD (* )(struct sbl_callback_context *))entrypoint;

 	//printf("ELF image loaded & relocated at %lx. Jumping!\n", entrypoint);

 	//printf("Debug info: load address now is %08lx\n", load_addr);
 	//getc();
 	result = bls(context);
 /*
 	if(result == SBL_PROTOCOL_TOO_OLD)
 	{
 		//printf("Using older interface \n");
 		degrade_to_old_frigging_interface(context);
 		result = bls(context);//and tries again!
 	}
 */
 	interpret_sbl_failure(result);
 }

 static BOOL is_good_bootsource(const char * const str)
 {
   /* Table as follows, from bios_menu.c
      floppy -> internal floppy (not yet supported)
      cdrom  -> ide CDROM(s)
      ide    -> ide disk(s)
      net    -> TFTP
      scdrom -> SCSI CDROM(s)
      scsi   -> SCSI disk(s)
      ucdrom -> USB CDROM(s)
      usb    -> USB disk(s)

   */
   if(find_dae(str))
     return TRUE;

   return FALSE;
 }

 #define CHECK_IMAGE_AND_ZERO_IF_BAD(pnt) \
 	if(!valid_elf_image(pnt)) \
 		{ \
 		free(pnt);\
 		pnt = 0;\
 		printf("bad ELF image loaded; skipping!");\
 		} \
 	else printf("found AOS4 SLB\n");

 int do_boota(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
 {
 	/* - Scan sequenziale secondo le variabili boot(x).
 	   - Se è forzata una selezione di media type,
 	   - si cerca quella.
 	   - se non si trova, si ricomincia.
 	   - Quindi la funzione di scansione ritorna vero se si è trovato qualcosa; in ingresso dovrà
 	     prendere il tipo di device che si vuole.
 	*/
 	char *env;
 	static char *argarray[5] = { 0 };
 	UWORD argcnt=0;
 	ULONG sector_size;
 	SCAN_HANDLE scanner = NULL;
 	void *sbl_buffer = NULL;
 	short TFTP_options_backup = TFTP_quit_on_error;

     console_row = 12;
     console_col = 0;
     video_clear();

 	TFTP_quit_on_error = TRUE;

 	//dump_silly_info();

 	blockbuffer = alloc_mem_for_iobuffers(MAX_BLOCKSIZE);

 	PRINTF("First-level bootloader: entered main\n");
 	//Right now argc and argv are ignored....

 	//Builds the set of strings to boot from. This is passed as "scan_list" to the lowlevel functions.

 	env = getenv("boot1");
 	if(env) {
 		PRINTF("found: %s\n",env);
 		if(is_good_bootsource(env)) argarray[argcnt++]=env;
 	}

 	env = getenv("boot2");
 	if(env) {
 		PRINTF("found: %s\n",env);
 		if(is_good_bootsource(env)) argarray[argcnt++]=env;
 	}

 	env = getenv("boot3");
 	if(env) {
 		PRINTF("found: %s\n",env);
 		if(is_good_bootsource(env)) argarray[argcnt++]=env;
 	}

 	PRINTF("First-level bootloader: got %u valid boot sources\n", argcnt);
 	puts("AOS4 FLB\n");

 	if(!argcnt) //No variables set ?
 		return 0;

 	argarray[argcnt]=(char *)0; //0 terminates.

 	for(scanner = start_unit_scan((void *)argarray, &sector_size);
       scanner;
       scanner = next_unit_scan(scanner, &sector_size))
 	{
 		switch(scanner->ush_device.type) //Here we make distinctions between the different media boot types.
 		{
 			case DEV_TYPE_HARDDISK:
 			{
 				ULONG p_loc;
 				//printf("Scanning HDD %s %s %s", scanner->ush_device.vendor, scanner->ush_device.product, scanner->ush_device.revision);
 				p_loc = find_secondary_bootloader_start_HD(sector_size);

 				PRINTF("Found an HD\n");
 				if(p_loc != (ULONG)-1) //Found something!
 				{
 					ULONG sbl_length = 0, io_res;
 					//void * base_address;

 					PRINTF("FLB: found something\n");

 					io_res = secondary_bootloader_length(p_loc, sector_size, &sbl_length);

 					if(io_res == LOAD_OK)
 					{
 						PRINTF("FLB: SLB of length %lu; loading\n", sbl_length);
 						sbl_buffer = alloc_mem_for_bootloader(sbl_length);
 						load_secondary_bootloader(p_loc, sbl_buffer, sector_size, sbl_length);
 						//printf("Success!\n");
 						CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
 					}
 				}

 				break;
 			}

 			case DEV_TYPE_CDROM:
 			{
 				//El Torito style booting.
 				disk_partition_t p_info;
 				block_dev_desc_t * blockdev = get_lowlevel_handler(scanner);

 				printf("Scanning CD/DVD %s %s %s", scanner->ush_device.vendor, scanner->ush_device.product, scanner->ush_device.revision);

 				PRINTF("Found a CD\n");
 				get_partition_info(blockdev, 0, &p_info);
 				sbl_buffer=alloc_mem_for_bootloader(p_info.size*p_info.blksz);
 				PRINTF("AOS CD boot partition on disk is %lu sectors long.\n", p_info.size);

 				/*
 				readsec = p_info.size / p_info.blksz;
 				if((p_info.blksz * readsec) < p_info.size)
 					readsec++; // PPC optimized!
 				*/

 				if(blockdev->block_read(blockdev->dev, p_info.start, p_info.size, sbl_buffer) != p_info.size)
 				{
 					puts(" read error when trying to load CD secondary booter\n");
 					free(sbl_buffer);
 					sbl_buffer=0;
 				}
 				else
 				{
 					PRINTF("CD boot image (el Torino) loaded.");
 					CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
 				}
 				break;
 			}

 			case DEV_TYPE_NETBOOT:
 			{
 				//Ok, here we try to load the secondary bootloader via TFTP
 				int transfer_size;
 				void * temp;
 				/* allocates memory for bootloader. Since the uboot very broken implementation
 				   of tftp doesn't support the newer extensions, I can't get the damn file size.
 				   What the heck, the tftp functions might even choke if the server sends any
 				   extension. So a "reasonably big" amount of memory is allocated. */
 				temp = alloc_mem_for_bootloader(BOOTLOADER_MAX_BUFFER);

 				env = getenv("netboot_file");
 				if (env == NULL) env = "OS4Bootloader";

 				PRINTF("Starting Net booting procedure; looking for bootloader. Load address will be %lx\n", temp);
 				puts("Starting Net booting procedure\n");
 				if ((transfer_size = my_NetLoop(env, temp)) != -1)
 				{
 					//Success.
 					sbl_buffer = temp;
 					CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
 					puts("Successfully loaded SLB from network\n");
 					break;
 				}
 				else printf("Couldn't download %s from network.\n",env);
 				free(temp);
 				break;
 			}

 			default:
 				printf("No known boot method for device type %d\n", scanner->ush_device.type);
 		}


 		if(sbl_buffer) //Already loaded ? Then skip the other units (devices).
 			break;
 	}

 	end_unit_scan(scanner);
 	end_global_scan();

 	if(sbl_buffer)
 	{
 		struct sbl_callback_context * cbc = build_callback_context(argarray);
 		//Should it be bootmedia instead of foundmedia ?
 		//ULONG *temp=(ULONG *)sbl_buffer;

 		PRINTF("FLB: SLB loaded; now launching it\n");

 		//New version: loads up an ELF image!
 		start_secondary_bootloader(sbl_buffer, cbc);
 	}
 	else
 	{
 		puts("FLB: no SLB found in any of the designated boot sources; returning to u-boot.\n");
 	}

 	TFTP_quit_on_error = TFTP_options_backup;

 	puts("Press any key to continue\n");
 	getc();

 	return 0;
 }

 /* Uboot 1.0.0 support here. */
 U_BOOT_CMD(
 	boota,      1,      0,      do_boota,
 	"start AmigaOS boot procedure",
 	". 'Boota' allows to boot AmigaOS alike OSes on Sam\n"
 //	". 'Boota' is a great command, that enables you to do things that before\nwere only dreamt of.\nNamely, booting AmigaOS4 on an A1.\nAside from that, it takes no arguments, so any extended help is of no help.\nOn the other hand, it uses a bunch or ruthless environment variables to work, so you might want some insight into these insightful matters.\nFirst of all, come the three 'bootmedia' twins, named 'boot1', 'boot2' and\n'boot3' (we have three of them so they are one more of the Friedens).\nEach of these can be set to a corresponding boot source that will be scanned,\nstarting - guess which one - from 'boot1'. Allowed boot sources are 'net' AKA\nbroken-TFTP-booting-dont-try-me, 'cdrom', 'ide', that are IDE/ATAPI CDRom and\nHDD,respectively, 'scdrom' and 'scsi', same as above but for SCSI and finally\n'ucdrom' and 'usb', meaning of which is left to figure out only to the smartest of you.\nBooting from floppy is not yet supported and when ready will probably leave someone still guessing what is it useful for (greetings to Elwood and Martin S).\nIf you decide to give control to this crazy bunch of buggy bits, it'll try to\nload the second-stage bootloader from the boot sources specified, and pass\ncontrol to it.\nOnce the second-stage bootloader takes control, it'll scan for available\nkickstart configurations, prompt the deepest corner of your soul for which\nconfiguration to load, and then start the REAL fun\n(... or at least attempt to).\nHave a nice day."
 );
	/* cmd_boota.c , AKA the AOS 4.x primary bootloader.
	Idea, design and (broken) code by Andrea Vallinotto.
	Have fun, have phone, have gun, etc...
	*/

	#include <common.h>
	#include <command.h>
	#include "cmd_boota.h"
	#include "sys_dep.h"
	#include "slb/sbl_errcodes.h" //For the error codes.
	#include <malloc.h>
	#include "net.h"
	#include <../net/tftp.h>
	#include <asm/processor.h>
	#include <asm/io.h>
	#include <asm/mmu.h>
	#include <asm/4xx_pcie.h>
	#include <asm/gpio.h>

	#undef DEBUG
	#ifdef DEBUG
	#define PRINTF(fmt,args...) printf (fmt ,##args)
	#else
	#define PRINTF(fmt,args...)
	#endif

	#define MAX_BLOCKSIZE 32768 //This is the PHYSICAL size, not logical!!
	#define ENV_VAR_BUFLEN 256

	extern int console_col; /* cursor col */
	extern int console_row; /* cursor row */

	static char * blockbuffer ; //IO buffer used many times.

	static void interpret_sbl_failure(const WORD err)
	/* Codes are as follows:
	(see slb/sbl.h)
	*/
	{
	char * stringout;

	switch(err)
	{
	case SBL_COULDNT_INIT:
	stringout = "Couldn't initialize second-level bootloader (out of memory ?).\n";
	break;

	case SBL_PROTOCOL_TOO_OLD:
	stringout = "Second level bootloader is too old; please upgrade it.\n";
	break;

	case SBL_PROTOCOL_TOO_NEW:
	stringout = "Second level bootloader requires a newer BIOS version; please upgrade.\n";
	break;

	case SBL_NO_CONFIG_FILES_FOUND:
	stringout = "No configuration file found in any partitions.\n";
	break;

	case SBL_FAILED_LOADING_KERNEL_IMAGE:
	stringout = "Failed loading kernel (or kickstart) image file(s).\n";
	break;

	case SBL_UNKNOWN_ERROR:
	default:
	stringout = "Unknown return code from secondary bootloader.\n";
	break;
	}

	printf(stringout);
	}

	static BOOL good_checksum(const LONG * bl, const UWORD len)
	{
	ULONG chsum=0;
	UWORD cnt;

	for(cnt=0;cnt<len;cnt++)
	chsum+=*bl++;

	return (BOOL)(chsum==0);
	}

	static BOOL is_good_bootsector(const struct BootstrapCodeBlock * const bcb,
	const unsigned long blocksize)
	{
	//printf("Entered is_good_b.\n");
	if(bcb->bcb_ID == IDNAME_BOOTSTRAPCODE)
	{
	if(bcb->bcb_SummedLongs <= (blocksize>>2))
	{
	if(good_checksum((const LONG * const)bcb, bcb->bcb_SummedLongs))
	return TRUE;
	else
	{
	gpio_config(30, GPIO_OUT, GPIO_SEL, GPIO_OUT_1);
	printf("Bad checksum while reading second level bootloader\n");
	}
	}
	else printf("Bad block structure while reading second level bootloader: summedlongs not good: %lu instead of %lu\n", bcb->bcb_SummedLongs, blocksize>>2);
	}
	// else printf("Bad identifier\n");
	//bcb_Next is not checked. Too complex.

	return FALSE;
	}

	static ULONG find_secondary_bootloader_start_HD(const unsigned long blocksize)
	{
	ULONG currsec = 0;

	PRINTF("Entered find_sec_bl_start %d %p\n",blocksize,blockbuffer);

	if ( ! blocksize) return (ULONG)-1;
	if ( ! blockbuffer) return (ULONG)-1;

	while(loadsector(currsec, blocksize, 1, blockbuffer))
	{
	PRINTF("Reading sector %lu\n", currsec);

	if(is_good_bootsector((struct BootstrapCodeBlock *)blockbuffer, blocksize))
	return currsec;

	/* printf("Sector %lu is bad: signature is %lx (should be %x)\n", currsec,
	((ULONG )blockbuffer), IDNAME_BOOTSTRAPCODE);
	*/
	if(++currsec > SBL_HIGHEST)
	return (ULONG)-1;
	}
	PRINTF("Loadsector failed\n");

	return (ULONG)-1; //This means a read error.
	}

	static ULONG secondary_bootloader_length(ULONG start_sect, const UWORD blocksize, ULONG * const dest_len)
	{
	ULONG next = start_sect, res=0;
	BOOL readres;
	struct BootstrapCodeBlock * bcb = (struct BootstrapCodeBlock *)blockbuffer;

	do {
	readres = loadsector(next, blocksize, 1, blockbuffer);

	if(!readres)
	{
	//printf("Bad IO while counting sectors for the s.bootloader image.\n");
	*dest_len = res;
	return (READ_ERROR\|(next & 0xffff));
	}

	if(!is_good_bootsector((struct BootstrapCodeBlock *)blockbuffer, blocksize))
	return (READ_SYNTAX_ERR\|next);

	/*
	if(res == 0) //First sector ? Then record start address (first longword)
	{
	struct BootstrapCodeBlock * helper = blockbuffer;
	*start_address = helper->bcb_LoadData[0]; //First longword of first block.
	}
	*/
	res++;
	}
	while((next=bcb->bcb_Next) != UNUSED_BLOCK_ADDRESS);

	res--; // Excludes last sector.
	res *= (blocksize - HEADER_INFO_SIZE); // -20 is to exclude header information.
	res += ((bcb->bcb_SummedLongs<<2) - HEADER_INFO_SIZE); //Last sector.

	*dest_len = res;
	return LOAD_OK;
	}

	static void load_secondary_bootloader(ULONG start_sect, char * dest_buffer, const UWORD blocksize,
	const ULONG len)
	{
	/* No error check is made, so be careful everything's ok before calling */
	ULONG nextsec=start_sect, chunklen;
	char * copystart = blockbuffer + HEADER_INFO_SIZE;
	ULONG * current = (ULONG *)dest_buffer;
	struct BootstrapCodeBlock * bcb = (struct BootstrapCodeBlock *)blockbuffer;

	do
	{
	loadsector(nextsec, blocksize, 1, blockbuffer);
	//lprintf("Reading sector %lu for lseg image\n", nextsec);
	//mycopymem(copystart, (char *)current, (chunklen=bcb->bcb_SummedLongs-(HEADER_INFO_SIZE>>2))<<2);
	memcpy((char *)current, copystart, (chunklen=bcb->bcb_SummedLongs-(HEADER_INFO_SIZE>>2))<<2);
	current+=chunklen;
	}
	while((nextsec=bcb->bcb_Next) != UNUSED_BLOCK_ADDRESS);
	}

	static void start_secondary_bootloader(void * start, struct sbl_callback_context * context)
	{
	WORD (* bls)(struct sbl_callback_context *);
	//void * realstart = ((char *)start)+4; //To skip the header. Remove for final version.
	//((char *)start)+offset;
	unsigned long entrypoint;
	WORD result;

	//icache_enable();
	//printf("Second-level bootloader loaded at %p; now checking.\n", start);
	//if(!valid_elf_image(realstart))
	if(!valid_elf_image(start))
	{
	printf("Error: no real ELF image installed as bootloader!\n");
	return;
	}
	//else printf("Image file is valid! Now elf-loading & relocating.\n");

	//entrypoint = load_elf_image(realstart);
	entrypoint = load_elf_image(start);
	bls = (WORD (* )(struct sbl_callback_context *))entrypoint;

	//printf("ELF image loaded & relocated at %lx. Jumping!\n", entrypoint);

	//printf("Debug info: load address now is %08lx\n", load_addr);
	//getc();
	result = bls(context);
	/*
	if(result == SBL_PROTOCOL_TOO_OLD)
	{
	//printf("Using older interface \n");
	degrade_to_old_frigging_interface(context);
	result = bls(context);//and tries again!
	}
	*/
	interpret_sbl_failure(result);
	}

	static BOOL is_good_bootsource(const char * const str)
	{
	/* Table as follows, from bios_menu.c
	floppy -> internal floppy (not yet supported)
	cdrom -> ide CDROM(s)
	ide -> ide disk(s)
	net -> TFTP
	scdrom -> SCSI CDROM(s)
	scsi -> SCSI disk(s)
	ucdrom -> USB CDROM(s)
	usb -> USB disk(s)

	*/
	if(find_dae(str))
	return TRUE;

	return FALSE;
	}

	#define CHECK_IMAGE_AND_ZERO_IF_BAD(pnt) \
	if(!valid_elf_image(pnt)) \
	{ \
	free(pnt);\
	pnt = 0;\
	printf("bad ELF image loaded; skipping!");\
	} \
	else printf("found AOS4 SLB\n");

	int do_boota(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
	{
	/* - Scan sequenziale secondo le variabili boot(x).
	- Se è forzata una selezione di media type,
	- si cerca quella.
	- se non si trova, si ricomincia.
	- Quindi la funzione di scansione ritorna vero se si è trovato qualcosa; in ingresso dovrà
	prendere il tipo di device che si vuole.
	*/
	char *env;
	static char *argarray[5] = { 0 };
	UWORD argcnt=0;
	ULONG sector_size;
	SCAN_HANDLE scanner = NULL;
	void *sbl_buffer = NULL;
	short TFTP_options_backup = TFTP_quit_on_error;

	console_row = 12;
	console_col = 0;
	video_clear();

	TFTP_quit_on_error = TRUE;

	//dump_silly_info();

	blockbuffer = alloc_mem_for_iobuffers(MAX_BLOCKSIZE);

	PRINTF("First-level bootloader: entered main\n");
	//Right now argc and argv are ignored....

	//Builds the set of strings to boot from. This is passed as "scan_list" to the lowlevel functions.

	env = getenv("boot1");
	if(env) {
	PRINTF("found: %s\n",env);
	if(is_good_bootsource(env)) argarray[argcnt++]=env;
	}

	env = getenv("boot2");
	if(env) {
	PRINTF("found: %s\n",env);
	if(is_good_bootsource(env)) argarray[argcnt++]=env;
	}

	env = getenv("boot3");
	if(env) {
	PRINTF("found: %s\n",env);
	if(is_good_bootsource(env)) argarray[argcnt++]=env;
	}

	PRINTF("First-level bootloader: got %u valid boot sources\n", argcnt);
	puts("AOS4 FLB\n");

	if(!argcnt) //No variables set ?
	return 0;

	argarray[argcnt]=(char *)0; //0 terminates.

	for(scanner = start_unit_scan((void *)argarray, &sector_size);
	scanner;
	scanner = next_unit_scan(scanner, &sector_size))
	{
	switch(scanner->ush_device.type) //Here we make distinctions between the different media boot types.
	{
	case DEV_TYPE_HARDDISK:
	{
	ULONG p_loc;
	//printf("Scanning HDD %s %s %s", scanner->ush_device.vendor, scanner->ush_device.product, scanner->ush_device.revision);
	p_loc = find_secondary_bootloader_start_HD(sector_size);

	PRINTF("Found an HD\n");
	if(p_loc != (ULONG)-1) //Found something!
	{
	ULONG sbl_length = 0, io_res;
	//void * base_address;

	PRINTF("FLB: found something\n");

	io_res = secondary_bootloader_length(p_loc, sector_size, &sbl_length);

	if(io_res == LOAD_OK)
	{
	PRINTF("FLB: SLB of length %lu; loading\n", sbl_length);
	sbl_buffer = alloc_mem_for_bootloader(sbl_length);
	load_secondary_bootloader(p_loc, sbl_buffer, sector_size, sbl_length);
	//printf("Success!\n");
	CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
	}
	}

	break;
	}

	case DEV_TYPE_CDROM:
	{
	//El Torito style booting.
	disk_partition_t p_info;
	block_dev_desc_t * blockdev = get_lowlevel_handler(scanner);

	printf("Scanning CD/DVD %s %s %s", scanner->ush_device.vendor, scanner->ush_device.product, scanner->ush_device.revision);

	PRINTF("Found a CD\n");
	get_partition_info(blockdev, 0, &p_info);
	sbl_buffer=alloc_mem_for_bootloader(p_info.size*p_info.blksz);
	PRINTF("AOS CD boot partition on disk is %lu sectors long.\n", p_info.size);

	/*
	readsec = p_info.size / p_info.blksz;
	if((p_info.blksz * readsec) < p_info.size)
	readsec++; // PPC optimized!
	*/

	if(blockdev->block_read(blockdev->dev, p_info.start, p_info.size, sbl_buffer) != p_info.size)
	{
	puts(" read error when trying to load CD secondary booter\n");
	free(sbl_buffer);
	sbl_buffer=0;
	}
	else
	{
	PRINTF("CD boot image (el Torino) loaded.");
	CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
	}
	break;
	}

	case DEV_TYPE_NETBOOT:
	{
	//Ok, here we try to load the secondary bootloader via TFTP
	int transfer_size;
	void * temp;
	/* allocates memory for bootloader. Since the uboot very broken implementation
	of tftp doesn't support the newer extensions, I can't get the damn file size.
	What the heck, the tftp functions might even choke if the server sends any
	extension. So a "reasonably big" amount of memory is allocated. */
	temp = alloc_mem_for_bootloader(BOOTLOADER_MAX_BUFFER);

	env = getenv("netboot_file");
	if (env == NULL) env = "OS4Bootloader";

	PRINTF("Starting Net booting procedure; looking for bootloader. Load address will be %lx\n", temp);
	puts("Starting Net booting procedure\n");
	if ((transfer_size = my_NetLoop(env, temp)) != -1)
	{
	//Success.
	sbl_buffer = temp;
	CHECK_IMAGE_AND_ZERO_IF_BAD(sbl_buffer);
	puts("Successfully loaded SLB from network\n");
	break;
	}
	else printf("Couldn't download %s from network.\n",env);
	free(temp);
	break;
	}

	default:
	printf("No known boot method for device type %d\n", scanner->ush_device.type);
	}


	if(sbl_buffer) //Already loaded ? Then skip the other units (devices).
	break;
	}

	end_unit_scan(scanner);
	end_global_scan();

	if(sbl_buffer)
	{
	struct sbl_callback_context * cbc = build_callback_context(argarray);
	//Should it be bootmedia instead of foundmedia ?
	//ULONG temp=(ULONG )sbl_buffer;

	PRINTF("FLB: SLB loaded; now launching it\n");

	//New version: loads up an ELF image!
	start_secondary_bootloader(sbl_buffer, cbc);
	}
	else
	{
	puts("FLB: no SLB found in any of the designated boot sources; returning to u-boot.\n");
	}

	TFTP_quit_on_error = TFTP_options_backup;

	puts("Press any key to continue\n");
	getc();

	return 0;
	}

	/* Uboot 1.0.0 support here. */
	U_BOOT_CMD(
	boota, 1, 0, do_boota,
	"start AmigaOS boot procedure",
	". 'Boota' allows to boot AmigaOS alike OSes on Sam\n"
	// ". 'Boota' is a great command, that enables you to do things that before\nwere only dreamt of.\nNamely, booting AmigaOS4 on an A1.\nAside from that, it takes no arguments, so any extended help is of no help.\nOn the other hand, it uses a bunch or ruthless environment variables to work, so you might want some insight into these insightful matters.\nFirst of all, come the three 'bootmedia' twins, named 'boot1', 'boot2' and\n'boot3' (we have three of them so they are one more of the Friedens).\nEach of these can be set to a corresponding boot source that will be scanned,\nstarting - guess which one - from 'boot1'. Allowed boot sources are 'net' AKA\nbroken-TFTP-booting-dont-try-me, 'cdrom', 'ide', that are IDE/ATAPI CDRom and\nHDD,respectively, 'scdrom' and 'scsi', same as above but for SCSI and finally\n'ucdrom' and 'usb', meaning of which is left to figure out only to the smartest of you.\nBooting from floppy is not yet supported and when ready will probably leave someone still guessing what is it useful for (greetings to Elwood and Martin S).\nIf you decide to give control to this crazy bunch of buggy bits, it'll try to\nload the second-stage bootloader from the boot sources specified, and pass\ncontrol to it.\nOnce the second-stage bootloader takes control, it'll scan for available\nkickstart configurations, prompt the deepest corner of your soul for which\nconfiguration to load, and then start the REAL fun\n(... or at least attempt to).\nHave a nice day."
	);